Dental casting machine



g M. F. BURNS 1503314 DENTAL CASTING MACHINE Filed Nov. '21. 1922 3 Sheets-Sheet 1 66 6/ I62 60 if? 4 &1

IN V EN TOR Mar/m FEZZ7W6 BY5%/%M A TTORNE Y 4 1 2 t m a 0 sm Kw s l t e e h s 3 m ,wn SAG. N GL um ww CN .Ld Mum Ni EF Aug. 5 1924.

IN V EN TOR fl/arl'z'n ZZBurn 5 W W W n m m T. A

7 to telescope thereon Patented Aug. 5, 1924.

SATES Q o I Maarm r. sue-us, or rwsarns, NEW YORK,

DENTAL CASTING MACHINE.

Application filed November 21, 1922.

To all whom it may concern Be it known that I, MARTIN F. BURNS, a citizen of the United States, and a resident of Flushing, county of Queens, and State of New York, have invented certain newand useful Improvements in Dental Casting Machines, of which the following is a specification. i v

The invention relates to dental casting machines used for casting plates, bridges, inlays and other restorations.

In casting a plate, bridge or other restoration, a dentist first makes a pattern in wax of the article to be cast. The pattern is then placed in an investment holder and is melted out or otherwise dissipatedand thecavity is filled with molten metal. The metal is forced into the cavity under pres sure to effect the complete filling of the cavity. The casting is then allowed to cool and is preferably cooled slowly to prevent warping or distortion.

The pressure utilized in the casting process is usually derived from compressed air and in casting machlnes now muse this compressed air is taken from air tanks or compressed air systems. a

This invention has for its salient object to provide a simple, practical, inexpensive and self-contained dental casting unit; or ap paratus so constructed that the air is com pressed by the apparatus during the operation thereof.

Another object of the invention isto provide apparatus of the class described having its operative parts adjustable to a plurailty of working positions whereby the de gree of compression of the air therein can be varied.

Further objects of the invention will appear from the following description taken in connection with the drawings which form a part of this application and in which, 1

Fig. 1 is a sectional elevation of one form of apparatus constructed in accordance with the invention, the base and member adapted beingshown in separated position.

Fig. 2 isa view similar to Fig. 1 but showing the parts in operative position, the

upper member being telesco-ped on the base.

Fig. 3 is a detail sectional view taken substantially on line 33 of Fig. 2.

Fig. 4 is a top plan view of one of the supporting members for the dental flask.

Serial No. 602,448.

Fig. 5 is a sectional elevation similar to F ig. 2 but showing another form of the apparatus.

The invention brieflydescribed comprises a base having means for supporting a dental flask and a member adapted to telescope on said base and to compress air between the member and the base as, the member is moved to telescoping position. Means are also provided for directing the compressed air to the flask and for sealing the parts so as to confine the air and to direct it into the flask. Further details of the invention will appear from the following description. 1 i r The apparatus comprises a base having a substantially cylindrical member 11 mounted thereon, the member 11 having an upper supporting surface 12 extending transversely thereof. The surface 12 in turn carries or has formed integrally therewith and disposed centrally with reference thereto, a receptacle 13 having 'a plurality of sets'of vertically spaced supporting lugs 14 extending inwardly from the inner surface thereof. The lugs 14 are adapted to support members 15 which in turn support the dental flask.

The members 15 are substantially cylindrical in shape and have flanges 16 extending laterally from thenp-per edges thereof.

As illustrated in Figs. 1,2 and 5 a plurality of these flask supporting members is providecl, these members having different dimensions or being of different depth so that the flask may be supported at different levels in the base of the casting machine. Each of the members 15 has formed in the flange 16 thereof notches 17 so formed that the lugs 14 will pass through these notches in case it is desired to support the member 15 on the'lower set of lugs 14. Each of the plurality of perforations 18 for permitting the nassa e of air therethrou 'h during the b C" u casting process. With two flask supporting flask supports 15 also has formed therein a drawings comprises an outer'receptacle 19 and an investment holder 20 supported thereon and disposed therein. The drawings also illustrate the investment 21 in the investment holder, a cavity 22 to be filled with metal during the casting and the molten metal 23 disposed in a concave depression 2st in the investment; The metal "drieal portion 11 of the base. telescoping operatio'n the air is compressed inthe bell shaped member 27 a nd it is there- "fore desirable-that the member-2'7 fit closely may be heated in any desired manner as by a blowpipe 25.

If desired the receptaclel3 may have heating means therein such as heating coils 13"for the purposeof heating the investment and "-waX' pattern and dissipating the wax.

A plurality of upright standards 26 is secured to the base lO and a'member 27 is 'slidably supported at'28 on the standards 26- 'and isa'dapted to telescope on the cylin- During the on the outer surface of the portion 11 of -'the"'base to prevent the air from escaping thereb'etween. This may be'accom'plished in any desired manner and in'the form. of the invention illustrated aflexible washer 29 "formed of any "suitable material such as leather issecured to the lower headed end o'f 'the' member 27 by a fiange30 formed on a sleeve 31 which is'threaded on the'lower end of the member 27. As the member 27 risrtelescoped on theportion 11 of the base this washer is bent upwardly as shown in Fig. 2'ther'eby fo'rminga seal.

Means are provided for directing the air compressed within the bell shaped member 27 to the dental flask and for confining the air during the casting operation. The bell shaped member 27 is provided with a transverse member 32 in Its upper portion, this meniber having a downwardly extending centrally disposed sleeve 33 formed thereon.

slidably mounted in the sleeve 33, the downward movement of this member being limited by a flange 39 formed on the upper *end of'the member 38 and engageable with the "upper surface of the member 32.

The tubular -member 38 has formed on its lower end a V-shaped groove or sealing ring 40 adapted, asshown in Fig. 2, to fit on the upper edge of the dental flask or of the investment holder 20 thereby confining the air to the flask.

thimble 41 is supported by a collar-4t2 in thereof.

'direction'by a spring 4:7 which engages at its lower end a flange 48 formed on'the member 43 and at its upper end the flange '34 formed on the sleeve 33. As abo-ve'stated the downward movement of the tubular member 38 is limited by the' fiange 39 formed thereon.

A gauge 50 is -mounted on the member 27 to indicate the air pressure therein.

Any suitable means may be used'for op- =erating the bell shaped telescoping member 27 and in the'embodiments of the invention illustrated this member hasarod 51 secured to the dome 36 thereof and extending upwardlytherefrom. This rod passes through a guide 52 'carriedb'ythe upright'standards 26 and means is provided on the guide 52 for retaining thememb'er 27 in elevated po sition. This retaining means consists of balls 53=resiliently actuated by springs 54 and engageable with notches or depressions 55 formed in the rod '51; 'As the member 27 is raised there'fo'rethe balls 53 will be forced into the depressions 55 thereby resili- '-ently,retaining the member 27 in elevated position.

The actuating means for the telescoping member consists of a lever 60 having a slot 61 in which is disposed a pin 62 carried by the rod 51. The lever 60 is fulcrumed on an adjustablepivot pin 63 carried by a collarGa carried by a sleeve 65 which in turn is" threaded on the upper end of one of the standards 26. Handles 66 are formed on the sleeve for facilitating the rotation As shown in 'Fig. 3 the lever 60 comprises a pair of bars67 each of these bars having a pin and slot connection with the pin 62 and each, of the bars being pivoted a' t'63 to the collar 64.

"Means is provided forlatchi'ng the lever after it has been depressed and this means is shown in detail in Fig. 3. The latching means consists of a pair of latching pawls 68 pivoted 011 acommon pivot 69 on'one of the standards 26. Aspring 70 is interposed "between the pawls and normally forces them outwardly, this movement being limited by lugs 71 formed on the lower ends of the pawls and engageable with stops 72 formed in the standard 26. When the lever is depressed the straps or bars 67 can pass downwardly over the latches until they engage a cross pin or stop 7 3 on the standard 26 and when the bars reach this position the pawls 68 will snap outwardly retaining the lever in this position. If further adjustment of the telescoping member is desired the lever fulcrum can be depressed by rotating the sleeve 65.

Since as above stated it is very desirable to have a closefit between the telescoping member 27 and the portion 11 of the base, the portion 11 is protected by a cylindrical casing 74: secured to the base and surrounding the outer finished surface of the base portion 11.

The apparatus above described operates in the following manner. When the pattern has been invested in the investment and the wax has been dissipated the flask is placed in the casting machine and the gold or other metal is melted in the cavity 24 in the investment. The blow pipe or other heating means is then withdrawn and the operator will depress the telescoping member 27 to the position shown in Fig. 2 by exerting force on the lever 60. During this telescoping of the member 27 on the base portion 11.

the tubular member 38 will be also depressed and the spring 47 will force the edge of the member 43 into sealing engagement with the groove 16 on the surface 12 of the base and will also force the sealing groove 40 on the lower end of the tubular member 38 into sealing engagement with the upper edge of the investment holder 20. Furthermore during this telescoping action or depression of the bell shaped member 27 air will be trapped therein and will pass upwardly through the openings 35 and subsequently downwardly through the air directing member 38 and through the thimble 4:1 into-the flask thereby forcing the gold into the cavity and forming a perfect casting. As the air is forced downwardly into the flask it may escape through the constricted openings 18 in the flask supporting member 15.

Attention is called to the fact that the air compressed and forced into the flask is warm air since it has been heated by the blow pipes. The lever and fulcrum adjusting member may be operated in such a manner as to apply the pressure gradually and to maintain a uniform'pressure after the de sired pressure has been reached.

The form of the invention illustrated in Fig. 5 differs from that already described in that the apparatus shown thereinhassupplement-al air compressing means. The base, bell shaped telescoping member and operating parts are substantially the same as those shown in the preceding figures. and there fore corresponding numbers have been used to indicate like parts.

In the embodiment of the invention shown in Fig, 5 however the rod 81 which corresponds to the rod 51 in Figs. 1 and 2 is not secured to the dome 36 of the bell shaped telescoping member 27. This rod in this instance is secured to a piston 82 and passes through an opening 83 in the dome 36 and a packing 84 prevents escape of the air through the opening. The piston 82 has formed thereon a downwardly extending sleeve 85 positioned in the tubular member 38 and this sleeve has formed therein a plurality of openings 86 for the admission of air to the interior of the sleeve.

The rod 81 is preferably hollow or longitudinally bored and a gauge 88 communicates with the upper portion of the rod and indicates the air pressure in the member 38.

In this form of the invention a compression spring 89 is mounted on each of the standards 26 and is disposed between the lugs 28 carried by the member 27 and the transverse guiding member 52. These springs normally urge the telescoping member 27 in a downward direction.

The device'shown in Fig. 5 operates in the following manner. As the lever is depressed the. rod 81 is released from the balls 53. The springs 89 will force the member 27 downwardly and the spring 4-7 will force the tubular member 38 into sealing position as shown in Fig. 2 and as described in connection with the other embodiment of the invention. As the member 27 is forced downwardly and telescopes over the base portion 11 air is compressed in the bell shaped member 27 and passes upwardly through the openings 35 and inwardly through the openings 86 to the interior of the piston sleeve 35. The air then passes downwardly through the air directing tubular member 38 and into the flask as with the other embodiment. When the member 27 has reached the position shown in Fig. 5 further depression of the rod 80 will cause the piston 82 to move downwardly in the tubular member 38 closing the openings 86 and trapping the air in the member 38. This operation will therefore further compress the air and force the air into the flask.

It will be seen from the foregoing specification that a single operation namely. the

operation of the lever, will effect the compression of the air and the direction of this compressed air to the dental flask and furthermore that this same operation will seal the parts in such a manner that the air will be confined and will effectively perform its function.

Although certain specific embodiments of the invention have been particularly illustrated and described it will be understood that the invention is capable of further modification and that further changes in the construction and in the arrangement of the various cooperating parts may be made Without departing from the spirit or scope ofthe invention as expressed in the following claims.

\Vhat I claim is 1. A dental casting machine comprising a pair of telescoping members, one of said members having a support for a dental flask relation and the air is compressed between the members.

3. A dental casting ma'chine'comprising a. pair of substantially cylindrical telescoping members, one of said-members having a support for a dental flask and the other memher having means for directing the air to said flask as said members are moved into telescoping relation and the air is compressed between the members.

4. A dental casting machine comprising-a pair 'ottelescoping members, one of said members having a support for a dental flask and the other member having means for directing the air to said flask as said members are moved into telescoping relation and the a base having air to said flask as said members are moved intotelescoping relation and the air is compressed between the members. I

8. A dental casting machine comprising a base having a 'su'port for a dental flask, a member adapted to telescope on said base and means slidably carried by and positioned within said member for directing air into said flask as said member is moved to telescoping position on said base. N

9.-A dental casting machine comprising a support for a dental flask, a member adapted to closely fit and telescope on said base and means slidably carried by and positioned Within said memher for directing air into said flask as said member is moved to telescoping position on said base.

10. A dental casting machine comprising a base having a support for a dental flask,

air is compressed between the members,

means for holding one of said members in a position spaced from the other member and means for latching said members in telescoping position.

5. A. dental casting machine comprising a pair of telescoping members, one of said members having a support for a dental flask and the other member having means for directing the air to saidflask as said members are moved into telescoping .re-

lation and the air is compressed between the members, andmeans including a lever for moving one of said members into"telescoping position on the other member.

6. A dental casting machine comprising a pair of telescoping members, one of said members having a support for a dental flask and the other member having. means for directing the air to said flask as said members are moved into telescoping relation and the air is compressed between the mem bers, mtans including a lever for moving one of said members into telescoping position on the other member, and means for adjusting the fulcrum of said lever.

7 A dental casting machine comprising a pair of telescoping members, one of said members having a plurality of adjustable,

supports for a dental flask and the other member having means for directing the a member adaptedtotelescope on said base, means slidably carried by and-positioned within said member for directing air into said flask as said member is moved to telescoping position on said base, and resilient means tendingto separate said means from said member.

11. A dental castingmachi'ne comprising a base having a support for a 'dentalflask, a member adapted to telescope on said base and means slidahlycarried by and positioned Within said member for directing air into said flask as said member is moved to telescopingfposition on said base, said slidable means having sealing means adapted to surround the flask and confine air therein.

12. A dental casting-machinecomprising a base having a support for a dental flask,

a member adapted to telescope on said base and means slidab'ly carried by and positioned Within said memberfor directing air'into said flask as said member is moved 'to telescoping position on said base,

"said slidable meanshaving sealing means adapted to engage the flask and confine air therein. v

13. A dental casting machine comprising a base having a support t'or a dental flask, a member adapted to telescope on said base and means slidably carried by and" posi tioned Within said member for directing 'air into saidflask as said nember is moved to able means having a plurality of sealin means adapted to surround the flask and confine air therein.

15. A dental casting machine comprising a base having a support for a dental flask, a member adapted to telescope on said base and means slidably carried by and positioned within said member for directing air into said flask as said member is moved to telescoping position on said base, said slidable means having a plurality of annular sealing means adapted to confine air in the flask as the air is directed thereto.

16. A dental casting machine comprising a base having a support for a dental flask, a member adapted to telescope on said base and means slidably carried by and positioned within said member for directing air into said flask as said member is moved to telescoping position on said base, said slidable means having sealing means adapted to surround the flask and confine air therein, and resilient means for forcing said sealing means into sealing position as said member is moved to telescoping position on said base.

17. A dental casting machine comprising a base having a supporting member ex tending transversely thereof, means carried by said member for supporting a dental flask, a member adapted to closely fit and telescope on said base and to compress air therebetween, and means carried by said telescoping member for directing the compressed air into said flask.

18. A dental casting machine comprising a base having a supporting member extending transversely thereof, means carried by said member for supporting a dental flask, a member adaptedto closely fit and telescope on said base and to compress air therebetween, andv means carried by said telescoping member for directing the compressed air into said flask, said means having a sealing element engageable with said supporting member for confining the air.

19. A dental casting machine comprising a base having a supporting member extending transversely thereof, means carried by said member for supporting a dental flask, a member adapted to closely fit and telescope on said base and to compress air therebetween, and means carried by said telescoping member for directing the'compressed air into said flask, said means having sealing elements engageable with said supporting member and with the flask for confining the air.

20. A dental casting machine comprising a base having a supporting member extending transversely thereof, means carried by said member for supportin a dental flask, a member adapted to closely fit and telescope on said base and to compress air therebetween, means carried by said telescoping member for directing the compressed air into said flask, said means having a sealing element engageable with said supporting member for confining the air, and resilient means for retaining said element in sealing position.

21. A dental casting machine comprising a base having a supporting member extending transversely thereof, means carried by said member for supporting a dental flask, a member adapted to closely fit and. telescope on said base and to compress air therebetween, means carried by said telescoping member for directing the compressed air into said flask, said means having sealing elements engageable with said supporting member and with the flask for confining the air, and resilient means for retaining said element in sealing position.

22. A dental casting machine comprising a base having a supporting member extending transversely thereof, means carried by said member for supporting a dental flask, a bell shaped member adapted to closely fit and telescope on said base and to compress air therebetween, and means carried by said telescoping member for directing the com pressed air into said flask.

23. A dental casting machine comprising base having a supporting member extending transversely thereof, means carried by said member for supporting a dental flask, a member adapted to telescope and closely fit on said base and to compress air therebetween, means carried by said telescoping member for directing the compressed air into said flask, and means for indicating the air pressure in said member.

24:- A dental casting machine comprising a base adapted to support a dental flask, a bell shaped member adapted to telescope on said base and compress air therebetween and supplemental air compressing means carried by said member.

25. A dental casting machine comprising a base adapted to support a dental flask, a bell shaped member adapted to telescope on said base and compress air therebetween, supplemental air compressing means carried by said member, and means for direct ing the air to said flask.

26. A dental castin machine comprising a base adapted to support a dental flask, a bell shaped member adapted to telescope on said base and compress air therebetween and supplemental air compressing means movably carried by said member.

27. A dental casting machine comprising a base adapted to support a dental flask, a bell shaped member adapted to telescope on said base and compress air therebetween, and supplemental air compressing means including a piston slidably carried by said member.

28. A dental casting machine comprising a base adapted" to support a dental flask, a bell shaped member adapted to telescope on said base and compress air therebetween, supplemental air compressing means mova'bly carried by said member, and means for indicating the air pressure in said supplemental air compressing means.

29. A dental casting machine comprising a base adapted to support a dental flask, a bell shaped member adapted to telescope on said base and compress air therebetween,

supplemental air compressing means including a piston slidably carried by said member, and means for indicating the air pressure in said piston.

30. A dental casting machine comprising a base adapted to support a dental flask, and a bell shaped member adapted to telescope on said base, and compress air therebetween.

31. A dental casting machine comprising a base having means for supporting a dental flask, a vertically movable member adapted to telescope on said base and compress air within the member, a lever for actuating said vertically movable member and means for holding said lever in adjusted position after said member has been lowered tooperative position.

32. A dental casting machine comprising a base having means for supporting a dental flask, a vertically movable, hollow bell shaped member disposed above said base and adapted to receive heated air as the metal in the flask is melted and relatively movable means carried by said member for directing the air downwardly into the flask as the bell shaped member is lowered to operative position.

33. A dental casting machine comprising a pair of telescoping members, one of said members having a support for a dental flask and the other member having means for directing the air to said flask and increasing the velocity of the air as said members are moved into telescoping relation and the air is compressed between the members.

34. A dental casting machine comprising a base having a support for a dental flask, a member adapted to telescope on said base, means slidably carried by and positioned within said member for directing air into said flask as said member is moved to telescoping position on said base, and means carried by said slidable means for increasing the air velocity as the air passes into the flask.

35. A dental casting machine comprising a-base having a support for a dental flask, a member adapted to telescope on said base, means slidably carried by and positioned within said member for directing air into said flask as said member is moved to telescoping position on said base, and means mounted in said slidable means for increas fhnglthe air velocity as the air passes into the as r.

36. A dental casting machine comprising a pair of telescoping'members, one of said members having a support for a dental flask and the other member having means for directing the air to said flask assaid members are moved into-telescoping. relation and the air is compressed between the members, and flexible sealing means for sealing the adjacent surfaces of the telescoping members when said v members are disposed in telescoping relation.

37. A dental casting machine comprising a base having means for supporting a dental flask and means including ahollow, bell shaped member adapted to telescope on said base for gradually applying air pressure to said flaskand main'tainiingtlie pressure con stant after the, desired pressure has been reached;.

In witness whereof, I have hereunto set my hand this-8th clay-of November,- 1922.

MARTIN F". BURNS. 

